The Experts below are selected from a list of 59871 Experts worldwide ranked by ideXlab platform
Yoshimasa Watanabe - One of the best experts on this subject based on the ideXlab platform.
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effect of intensive Membrane aeration and Membrane Flux on Membrane fouling in submerged Membrane bioreactors reducing specific air demand per permeate sadp
Separation and Purification Technology, 2015Co-Authors: Taro Miyoshi, Yoshimasa Watanabe, Hiroshi Yamamura, Toru MoritaAbstract:Abstract The effects of Membrane module configuration and Membrane Flux on specific air demand per permeate (SAD p ) required for stable operation of a submerged Membrane bioreactor (MBR) for treating municipal wastewater were investigated. An intensively aerated Membrane module was developed to reduce the Membrane fouling in submerged Membrane bioreactors. In this module, coarse bubbles can be introduced at higher density in the vicinity of the Membrane fibers, made of polytetrafluoroethylene (PTFE), which has a very high tensile strength (90–110 N/fiber) even though it has high porosity (about 80%). By applying the intensively aerated Membrane module developed in this study to pilot-scale MBRs, very low Membrane fouling rate was achieved during the continuous MBR operation. The observation of fiber movements using high speed camera revealed that the Membrane-fiber vibration in the intensively aerated module were apparently intensified compared with those in a conventional Membrane module. Reducing Membrane Flux was also beneficial for reducing SAD p . When the MBR equipped with the intensively aerated module, stable continuous MBR operation without any Membrane cleaning for two months under low SAD p (8.8 m 3 -air/m 3 -permeate) was achieved by lowering Membrane Flux to 16 L/m 2 h (or 0.4 m 3 /m 2 /day), even in the short Membrane height of 0.5 m. These results strongly suggest that there is still great room for improving the efficiency of Membrane aeration by optimizing hydrodynamics around Membrane modules.
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The difference in characteristics of foulants in submerged MBRs caused by the difference in the Membrane Flux
Desalination, 2008Co-Authors: Katsuki Kimura, Taro Miyoshi, Takuro Naruse, Nobuhiro Yamato, Rie Ogyu, Yoshimasa WatanabeAbstract:Abstract The main obstacle for a wider use of Membrane bioreactors (MBRs) for wastewater treatment is Membrane fouling, which increases operating costs. For a more efficient control of Membrane fouling in MBRs, an understanding of the mechanisms of Membrane fouling is important. We conducted two separate pilot-scale experiments using real municipal wastewater to investigate the influence of the Membrane Flux in MBRs on the characteristics of foulants, which were analyzed by Fourier transform infrared (FTIR) spectra, 13C nuclear magnetic resonance (NMR) spectra, monosaccharide composition and amino acid analyses. In each experiment, two identical Membrane modules were submerged in the same MBR tank and were operated under different Membrane Fluxes. The results obtained in this study indicated that the Membrane filtration Flux significantly influenced Membrane fouling in MBRs. Membrane fouling in the module operated with the higher Flux was much greater than that of the other on the basis of the volume of filtered mixed liquor suspension. Analyses of the foulants desorbed from the fouled Membranes revealed that the nature of the foulants significantly differed depending on the Membrane Flux despite the fact that the two modules filtered the same mixed liquor suspension at the same time. The difference in characteristics of the foulants caused by the difference in the Membrane Flux was similar in the two separate experiments, indicating that reproducibility of the data was sufficient. It was thought that different fractions of the mixed liquor suspension were transported to the surfaces of the Membranes depending on the Membrane Flux and subsequently caused Membrane fouling to different extents. The foulant desorbed from the Membrane operated with a higher Flux seemed to cause severer fouling than the foulant desorbed from the other Membrane.
Yuefeng F Xie - One of the best experts on this subject based on the ideXlab platform.
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effects of ph and temperature on forward osmosis Membrane Flux using rainwater as the makeup for cooling water dilution
Desalination, 2014Co-Authors: Wendong Wang, Yinting Zhang, Mariem Esparraalvarado, Xiaomao Wang, Hongwei Yang, Yuefeng F XieAbstract:Abstract Cooling water plays an important role in maintaining proper temperatures for many industrial processes. To compensate for water loss and to maintain proper cooling water quality, fresh water must be added to the circulating system. In this study, we evaluated the feasibility of forward osmosis using rainwater as the makeup water source for the cooling water. It was determined that the average water Flux was 1.75 L/(m 2 ·h) at 23 °C and decreased gradually to 0.65 L/(m 2 ·h) after the draw solution was diluted 4 times. Although the changes in pH had a small direct effect on the water Flux, the existence of sodium hydroxide would promote the dissolution of more carbon dioxide into the feed solution and thus inhibit the permeation process. However, the temperature showed a notable effect on the water Flux. By increasing the temperature of the draw solution from 3 °C to 50 °C, the Membrane Flux increased approximately 10 times. During the extended operation, no decreases in Flux were observed as a result of Membrane fouling, even when 50 mg/L kaolin or 25 mg/L sodium alginate was added to the feed solution.
Taro Miyoshi - One of the best experts on this subject based on the ideXlab platform.
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effect of intensive Membrane aeration and Membrane Flux on Membrane fouling in submerged Membrane bioreactors reducing specific air demand per permeate sadp
Separation and Purification Technology, 2015Co-Authors: Taro Miyoshi, Yoshimasa Watanabe, Hiroshi Yamamura, Toru MoritaAbstract:Abstract The effects of Membrane module configuration and Membrane Flux on specific air demand per permeate (SAD p ) required for stable operation of a submerged Membrane bioreactor (MBR) for treating municipal wastewater were investigated. An intensively aerated Membrane module was developed to reduce the Membrane fouling in submerged Membrane bioreactors. In this module, coarse bubbles can be introduced at higher density in the vicinity of the Membrane fibers, made of polytetrafluoroethylene (PTFE), which has a very high tensile strength (90–110 N/fiber) even though it has high porosity (about 80%). By applying the intensively aerated Membrane module developed in this study to pilot-scale MBRs, very low Membrane fouling rate was achieved during the continuous MBR operation. The observation of fiber movements using high speed camera revealed that the Membrane-fiber vibration in the intensively aerated module were apparently intensified compared with those in a conventional Membrane module. Reducing Membrane Flux was also beneficial for reducing SAD p . When the MBR equipped with the intensively aerated module, stable continuous MBR operation without any Membrane cleaning for two months under low SAD p (8.8 m 3 -air/m 3 -permeate) was achieved by lowering Membrane Flux to 16 L/m 2 h (or 0.4 m 3 /m 2 /day), even in the short Membrane height of 0.5 m. These results strongly suggest that there is still great room for improving the efficiency of Membrane aeration by optimizing hydrodynamics around Membrane modules.
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The difference in characteristics of foulants in submerged MBRs caused by the difference in the Membrane Flux
Desalination, 2008Co-Authors: Katsuki Kimura, Taro Miyoshi, Takuro Naruse, Nobuhiro Yamato, Rie Ogyu, Yoshimasa WatanabeAbstract:Abstract The main obstacle for a wider use of Membrane bioreactors (MBRs) for wastewater treatment is Membrane fouling, which increases operating costs. For a more efficient control of Membrane fouling in MBRs, an understanding of the mechanisms of Membrane fouling is important. We conducted two separate pilot-scale experiments using real municipal wastewater to investigate the influence of the Membrane Flux in MBRs on the characteristics of foulants, which were analyzed by Fourier transform infrared (FTIR) spectra, 13C nuclear magnetic resonance (NMR) spectra, monosaccharide composition and amino acid analyses. In each experiment, two identical Membrane modules were submerged in the same MBR tank and were operated under different Membrane Fluxes. The results obtained in this study indicated that the Membrane filtration Flux significantly influenced Membrane fouling in MBRs. Membrane fouling in the module operated with the higher Flux was much greater than that of the other on the basis of the volume of filtered mixed liquor suspension. Analyses of the foulants desorbed from the fouled Membranes revealed that the nature of the foulants significantly differed depending on the Membrane Flux despite the fact that the two modules filtered the same mixed liquor suspension at the same time. The difference in characteristics of the foulants caused by the difference in the Membrane Flux was similar in the two separate experiments, indicating that reproducibility of the data was sufficient. It was thought that different fractions of the mixed liquor suspension were transported to the surfaces of the Membranes depending on the Membrane Flux and subsequently caused Membrane fouling to different extents. The foulant desorbed from the Membrane operated with a higher Flux seemed to cause severer fouling than the foulant desorbed from the other Membrane.
Wendong Wang - One of the best experts on this subject based on the ideXlab platform.
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effects of ph and temperature on forward osmosis Membrane Flux using rainwater as the makeup for cooling water dilution
Desalination, 2014Co-Authors: Wendong Wang, Yinting Zhang, Mariem Esparraalvarado, Xiaomao Wang, Hongwei Yang, Yuefeng F XieAbstract:Abstract Cooling water plays an important role in maintaining proper temperatures for many industrial processes. To compensate for water loss and to maintain proper cooling water quality, fresh water must be added to the circulating system. In this study, we evaluated the feasibility of forward osmosis using rainwater as the makeup water source for the cooling water. It was determined that the average water Flux was 1.75 L/(m 2 ·h) at 23 °C and decreased gradually to 0.65 L/(m 2 ·h) after the draw solution was diluted 4 times. Although the changes in pH had a small direct effect on the water Flux, the existence of sodium hydroxide would promote the dissolution of more carbon dioxide into the feed solution and thus inhibit the permeation process. However, the temperature showed a notable effect on the water Flux. By increasing the temperature of the draw solution from 3 °C to 50 °C, the Membrane Flux increased approximately 10 times. During the extended operation, no decreases in Flux were observed as a result of Membrane fouling, even when 50 mg/L kaolin or 25 mg/L sodium alginate was added to the feed solution.
Shiang Q Fu - One of the best experts on this subject based on the ideXlab platform.
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effect of draw solution concentration and operating conditions on forward osmosis and pressure retarded osmosis performance in a spiral wound module
Journal of Membrane Science, 2010Co-Authors: Yuan Xu, Xiaoyu Peng, Chuyang Y Tang, Shiang Q FuAbstract:Forward osmosis (FO) and pressure retarded osmosis (PRO) are concentration-driven Membrane processes. While they can be potentially used in water, wastewater, and energy applications, these processes suffer from the concentration polarization inside the porous Membrane support resulting in severe Flux decrease, a phenomenon known as internal concentration polarization (ICP). Researchers have investigated the effect of ICP both in theoretical and experimental studies. The current study extends the existing ICP model to include the effect of draw solution dilution by Membrane permeate flow in a spiral wound FO module (SWFO). FO and PRO experiments were performed using a Hydrowell® SWFO under both submerged and cross-flow conditions. The effect of draw solution concentration, draw solution flow rate, feed water flow rate, and Membrane orientation on FO and PRO water Flux performance was systematically investigated. Permeate flow increased with greater draw solution concentration in both FO and PRO modes. ICP was found to drastically limit the available Membrane Flux in the concentration-driven Membrane processes, and its adverse effect was more severe at greater draw solution concentration. Membrane Flux was also affected by the dilution of draw solution when the permeate flow rate was comparable or greater than the draw solution flow rate. The submerged FO configuration performed nearly as good as the cross-flow configuration with feed water circulating outside of the Membrane envelope (shorter flow path). In this case, the feed water flow rate only had limited effect on Membrane Flux likely due to its low mass transfer resistance. In contrary, the Membrane Flux can be adversely affected at low feed water flow rate when it was circulated inside of the Membrane envelope (longer flow path).